In this activity, students build a basic understanding of how a sling psychrometer is used to determine relative humidity and learn how to read a chart to determine this relationship. In addition, the student will become familiar with the concept of...(View More) dew point. Materials need to conduct the investigation include two thermometers, a wooden dowel, wood screw, two washers, a section of plastic straw, and a hollow shoelace. The resource includes background information, teaching tips and questions to guide student discussion. This is chapter 11 of Meteorology: An Educator's Resource for Inquiry-Based Learning for Grades 5-9. The guide includes a discussion of learning science, the use of inquiry in the classroom, instructions for making simple weather instruments, and more than 20 weather investigations ranging from teacher-centered to guided and open inquiry investigations.(View Less)